Ionizing radiation can cause single event upsets (SEUs) in semiconductor ICs. Ionizing radiation can directly upset storage circuits, such as SRAMs, register files and flip-flops. Moreover, radiation events in combinational logic create voltage glitches that can be latched. SEUs may cause the IC to perform incorrect or illegal operations.
Methods to prevent SEUs include adding spatial and/or temporal redundancy, so that a single radiation event cannot cause an SEU. Redundancy solutions incur area, power and performance penalties. Consequently, there is a need to improve detection schemes of radiation events in ICs.
An array of SOI SRAM cells has been proposed to detect alpha particles from neutrons that interact with a neutron conversion layer. Alpha particles hitting the sensitive area of an SRAM cell cause an SEU. While the SEU rate of SRAMs from alpha particles is very large for high reliability applications, the sensitive area of an SRAM cell is a small fraction of the total cell area.
Another SOI ionizing radiation monitor consists of a diode below the buried oxide connected to a circuit, such as a domino circuit. This requires special process steps to form the diode below the BOX. Another SOI radiation detector consists of a PNPN structure in the active device layer and a PN gate. The detector enters a high current latchup state to detect radiation.
Accordingly, there exists a need in the art to overcome the deficiencies and limitations described hereinabove.